Comparative studies on detergents - chlorhexidinum gluconicum, ditalan wo hc, sodium-laurylsulphate, laurosept, nekal bx - used for homogenization of diagnostic specimens in the microbiological diagnostic of tuberculosis.

Between 1974 and 1978 there were carried out comparative studies concerning the value of several detergents used to homogenization of diagnostic specimens in six countries (Bulgaria, Czechoslovakia, German Democratic Republic, Poland, The Soviet Union and Yugoslavia). In the first study it was confirmed that the homogenization of diagnostic materials by detergents gives good results and is more economical than conventional Petroff's method. In the majority of centers the highest detection of tubercle bacilli was found after homogenization by Sodium-Laurylsulphated-technique. Remarkable differences in the time of growth of tubercle bacilli after homogenization of the same samples by Laurylsulphate, Laurosept and Petroff's lye method were not observed. While, after homogenization by Nekal BX the time of growth was a little bit retarded. In the lowest percentage of contamination was observed after homogenization by Nekal BX. In the second study the value of Polish detergents (Chlorhexidinum gluconicum and Laurosept) was compared with Ditalan OW hc made in GDR and with other routinely in the participating laboratories used techniques. The best results were obtained after homogenization of specimens by Chlorhexidinum gluconicum. But the comparison to Laurosept and Ditalan WO hc showed no significant differences. Homogenization of sputa was better and number of contaminations lower after using laurosept or Ditalan WO hc than by means of Chlorhexidinum gluconicum.